The stock feedneck is junk. I actually twisted the feedneck out of the top of the marker trying to remove my Halo, aside from that the stock set-up isn't bad. the barrel is reasonably accurate, the regulator is reasonably consistent, the board and eyes work like they should.
Overall I like this marker. I've since upgraded it with a Blackheart board, CP trigger, SP clamping feedneck, Shockteck LP regulator, Freak barrel system, SP firebolt, SP 360 QEV, SP S-rail and on-off ASA, NDZ fire chamber and swivel donut, Lucky spring detents, and have ordered a TechT Sleeper body to make maintenance easier. I can fire my typical 1000 rounds without needed to refill my 68/4500.
I've been using this marker for a little over two years in the woods, beat the crap out of it, and it always performs. The modular design makes upgrading easy, and there's a large variety of upgrades available to choose from. The only thing I'd like to point out is that using a QEV with a very light bolt like the TechT L7 is that the bolt will move forward fast enough to occasionally crack a ball in the breach. If you want an ultra light bolt, skip the QEV.

Conclusion:

I'd recommend this marker to people who like to tinker and upgrade and are capable of handling the upgrading themselves. If you're an entry level player who isn't proficient at modifying markers the Vibe is a better bet.
By the time you're done upgrading, the cost of the marker is in the $650 CDN range, but the performance is excellent. I'm giving the Ion a 9 because it is a basic platform that allows you to get exceptional performance as your budget allows, and I've had no reliability issues. I do not consider upgrading parts to be a negative issue, and aside from the stock feedneck, the marker is fine out of the box.